1. Localizing the maximum in an environmental field using a mobile sensor Signals, Instruments & SystemsSara Oppenheimer & Bruno Spahni

2. Plan Goal Experiment Results Conclusion

3. Goal |Experiments |Results |Conclusion Light (20W) Goal of the Project: Finding the location of maximal light in an environmental field. Tools: E-Puck -Go to the Light -LED indicate light’s direction - Stop near the light source - All LED turn on Two main steps:

4. Methodology of the robot: 1. Measures environmental informations 2. Analyses the data 3. Wheels and LED reaction 4. Stops if it’s near light Goal |Experiments |Results |Conclusion

5. An e-puck with: -8 IR sensors (we only use the receptor function) { i=0; for(i = 0;i <= 7;i++) { sample_single_light_sensor(i); while(sample_status!=2); } sprintf(buffer, "%lu,%lu,%lu,%lu,%lu,%lu,%lu,%lu\n\r",sample_buffer[0],sample_b uffer[1],sample_buffer[2],sample_buffer[3],sample_buffer[4],sam ple_buffer[5],sample_buffer[6],sample_buffer[7]); e_send_uart1_char(buffer, strlen(buffer)); while(e_uart1_sending());

6. Goal |Experiments |Results |Conclusion Go to the Light (2 Methods): 1 st : Create two variables with the sum of the right and left sensor’s values respectively. – The robot follows the direction of the lower addition value if(bufD > bufG){ e_set_speed_left(50); e_set_speed_right(100); } else{ e_set_speed_left(100); e_set_speed_right(50); } bufD = sample_buffer[0] +sample_buffer[1] +sample_buffer[2] +sample_buffer[3]; bufG = sample_buffer[4] +sample_buffer[5 ]+sample_buffer[6] +sample_buffer[7];

7. Goal |Experiments |Results |Conclusion Go to the Light (2 Methods): 2 nd : Find the sensor with the minimal value – Give a particular direction to the wheel for each sensor min = 8000; for(i=0;i<=7;i++) { if(sample_buffer[i]<=min){ min = sample_buffer[i]; captor = i; switch (captor) { case 0: e_set_speed_left(560); e_set_speed_right(500); e_set_led(0,1); break; case 1: //same set ups for 2&3 e_set_speed_left(300); e_set_speed_right(-300); e_set_led(1,1); break;

8. Goal |Experiments |Results |Conclusion

9. How to stop the robot near the light? (3codes) 1 st : When the sum of all sensors’ values is smaller than a fixed value. 2 nd : When the sum of the back sensors’ values is smaller than 1.5 times the sum of the front ones. 3 rd : Data storage in a vector  Comparison between stored and current data Goal |Experiments |Results |Conclusion if (sum_captor<3000){ e_set_speed_left(0); e_set_speed_right(0); all_LED_on(); } if (back_sum<(1.5*front_sum){ e_set_speed_left(0); e_set_speed_right(0); all_LED_on(); } if (sum_buffer ((1/5)*mean_buffer)){ e_set_speed_left(0); e_set_speed_right(0); all_LED_on();

10. Goal |Experiments |Results |Conclusion Perfect detection up to 4.5 [m] Regressing from 4.5 [m] to 7 [m] Up to 14 [m] in case of horizontal light Problems: Deviation to the right side Minicom indicates sensor 0 more sensitive than the others Results of following Light’s Direction

11. Goal |Experiments |Results |Conclusion

12. We varied two coefficients of the code Results of Stops near the Light Goal |Experiments |Results |Conclusion

13. Stop on right location : 7 & 1/7 Goal |Experiments |Results |Conclusion

14. We varied two coefficients of the code Results of Stops near the Light Goal |Experiments |Results |Conclusion

15. Stop before the light: 16 & 1/16 Goal |Experiments |Results |Conclusion

16. We varied two coefficients of the code Results of Stops near the Light Goal |Experiments |Results |Conclusion

17. No stop: 5 & 1/5 Goal |Experiments |Results |Conclusion

18. We varied two coefficients of the code Results of Stops near the Light Goal |Experiments |Results |Conclusion

19. Conclusion Quite satisfactory results Pay attention to the bias IT Project: importance of global view

20. Thanks for your attention Questions? Goal |Experiments |Results |Conclusion